Hyperlinks in hyperlink fields must use protocols supported by (!idspnSharePointFoundation_NV). Some protocols, such as telnet ...

Hyperlinks in hyperlink fields must use protocols supported by (!idspnSharePointFoundation_NV).  Some protocols, such as telnet and gopher, are not supported for security reasons.  Additionally, the value in a hyperlink field is restricted to 255 characters for the display text and 255 characters for the URL.